A to Z: Ventricular Tachycardia

Ventricular tachycardia (V-tach or VT) is a potentially life-threatening arrhythmia (abnormal heart rhythm) in which the heart beats too rapidly. It starts in the ventricles, the heart's pumping chambers.

More to Know

Ventricular tachycardia occurs when electrical signals in the heart muscle are sent too quickly. This is often due to an underlying heart problem such as an enlarged heart (cardiomyopathy), heart valve disease, coronary artery disease, or high blood pressure. Scar tissue that develops following a heart attack or heart surgery can also cause ventricular tachycardia, as can certain medications, electrolyte imbalances, recreational drugs, and other factors. In some cases the cause is unknown.

In addition to heart palpitations, or feeling like the heart is racing, symptoms of ventricular tachycardia may include shortness of breath, chest pain, light-headedness and dizziness.

Fainting, unconsciousness, cardiac arrest, and even death can occur when the heart rate is dangerously high or an episode of ventricular tachycardia lasts more than a few seconds. For this reason, it’s important to call 911 or go to the emergency room for treatment if you see signs of ventricular tachycardia.

Keep in Mind

While ventricular tachycardia is a very serious condition, many people see improvement when the underlying condition can be managed.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.